<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        #app {
            /* 设置弹性盒布局 */
            display: flex;
            height: 100vh;
            /* 是否允许换行 */
            /* flex-wrap: wrap; */
            /* 设置主轴方向 */
            flex-direction: column;
            /* 设置主轴对齐方式 */
            justify-content:space-between;
            /* 设置交叉轴对齐方式 */
            align-items: center;
        }

        #app div,p {
            width: 60px;
            height: 60px;
            border: 1px solid #369;
            margin-right: 10px;
        }
        p{
            margin: 0;
            justify-content: space-around;
        }
        #app div:nth-child(1){
            /* 设置子元素自身对齐方式 */
            align-self: flex-start;
            width: 90vw;
            display: flex;
            justify-content:space-between;
        }
    </style>
</head>

<body>
    <div id="app">
        <div>
            <p>1</p>
            <p>2</p>
            <p>3</p>
        </div>
        <div>2</div>
        <div>3</div>
        <div>4</div>
        <div>5</div>
        
    </div>
</body>

</html>